This article discusses the amount of free disk space required to run the Eseutil.exe program that ships with Microsoft Exchange Server version 5.5.

Eseutil.exe can be used to defragment, repair, or check the integrity of a Microsoft Exchange Server database.

The amount of free disk space needed to defragment a database (Eseutil /d) is 110 percent of the size of the file being defragmented.

When you repair a database (Eseutil /p), the amount of free disk space required depends on the number of corrupt pages in the database. This is different from how the older Edbutil.exe program repaired databases. Normally, 25 percent of the file being repaired is a conservative estimate of the amount of free disk space required.

Checking database integrity (Eseutil /g) is an in-place operation and does not require any additional free disk space.

In the case of the defrag or repair operations, the /t command line switch should be used to specify the location of a temporary file. This file should be located on a drive that has the required free disk space. This can be a local or a network drive.